A refill supply of the kind this invention modifies is shown in U.S. Pat. No. 4,760,409. That is a three dimensional structure generally having the outline of a brick or building block. That supply is mounted in the printer where a needle pierces a rubber stopper to connect ink in a bag in the supply through a tube to the printer. A second tube in the printer is connected back to the supply.
More specifically, this invention is a modification of the prior art supply sold by various firms including the assignee of this invention, which sells the supply as the IBM Ink Cartridge for the IBM 4072 Printer. That supply has ink in a bag resting on absorbent paper or felt, with an opening in the casing for a tube from the printer which returns excess ink. The casing is sealed, and the entire casing is discarded with each refill. The absorbent paper absorbs the return ink so that it is held in the casing.
In accordance with this invention the casing is hinged and the ink bag and absorbent paper are encased in an outer bag. Only the outer bag and its contents are discarded.
U.S. Pat. Nos. 5,023,629 to Kiyohara and 4,695,824 to Tazaki show variations of the foregoing type of supply. U.S. Pat. Nos. 4,928,126 to Asai and 4,183,031 to Kyser et al show ink supplies in a bag with the bag in a container. None of these patents are closely relevant to this invention since they do not teach an outer bag surrounding the ink bag and an absorbent material.